Before rubbing apples stiffened subjected to heating to achieve their softening to such an extent that their rubbing is made possible through the sieve.
Apples soften when podparke, because under the influence of heating and the acid present in them, hydrolysis of protopectin, located in cell walls and in intercellular spaces, develops. The other cells of the protopectin glued together are slightly separated, a part of the cells are torn, the fruits soften without losing form. If the heat is too weak, when the apples are not heated enough over the entire layer, they are too hard, not welded after the scalding. If the heat is too strong and prolonged in apples with a high acid content, a deep decomposition of the pectin substances occurs, which manifests itself in the digestion of apples and can lead to more or less weakening of the gel-forming ability of the puree. The latter is obtained with a too liquid consistency.
In the process of pulping, sterilization of the apple mass is achieved. Apples carry on their surface a microflora consisting mainly of yeast fungi. The latter are the causative agents of damage to apple puree. They destroy necessary for the production of valuable components of the apple (sugar, pectin, acid). The same applies, to a certain extent, to molds and bacteria on the surface of the fruit. At a temperature of 100 °, yeast and other microorganisms of the apple die, at a temperature of 115-120 ° and higher and prolonged heating, not only microorganisms die, but also their spores. The temperature and duration of the stocking are calculated in production in such a way that they provide complete practical sterilization of the apple mass. This significantly increases the firmness of apple puree in subsequent storage.
From other biochemical changes under the influence of spaghetti it is necessary to note the destruction of the oxidase system of apples (usually referred to as the enzyme malaz), on which the formation of dark colored products of oxidation of tannins in apples - flobafenes. In a healthy apple, its tannins and oxidizing enzyme system are not in the state of contact necessary for chemical interaction. When the fetal tissue is damaged, tannic substances come into contact with the enzymes, they become oxidized at the same time, which leads to a darkening of the tissue. The existence of malas in apples would create a danger of their darkening, especially when rubbed, thanks to the extensive development of the surface of the apple pulp. The high temperature of the scalding paralyzes the action of malaz, as well as other enzymes contained in the apple. Of the latter, one should point out pectolytic enzymes that break down pectin substances, as well as ascorbinase and invertase, which break down when podpark.
Of the secondary phenomena in scalding should also note the removal of air from the fabric shparenyh apples, the destruction of certain dyes contained in the apple. On the other hand, due to the partial caramelization of the sugars (especially fructose) by weight malic proshparennaya heating takes yellowish. This yellowing is stronger, the higher the temperature and pressure in shparochnom apparatus.
Apples produce steam or scalding water. Preferably use scalding steam, low pressure (about 1 - 2 atm). Shparochnogo pressure inside the device should not exceed 0,1-0,2 ati. In operation, a higher pressure may deep cleavage of pectin, as well as some yellowing puree influenced caramelization of sugar.
The duration of scalding 10-20 minutes.
From the point of view of preserving vitamin C in apple puree, it is very important that the scalding of apples pass at the most moderate temperature regime. According to the VNII , an increase in temperature in the storage space at 1-2 ° in excess of 100 ° leads to a sharp increase in the loss of vitamin C apples. When the apple pulp is to be created, conditions must be created that ensure a rapid heating of the apples, so that the total duration of the process does not exceed 10 min. Thus, in order to obtain a more fully pureed puree, it is necessary to combine the rapid heating of apples with the shearing mode, which excludes the effect of temperatures above 100 ° on apples.
The acceleration of large-fruited apples warm while scalding is achieved by carving an apple core along its longitudinal axis by means of a special machine.
At small enterprises, practice is practiced in the shaping of apples in water in ordinary steam boilers. With this method of work, the puree is significantly diluted and, in addition, the water that goes to the shear is extracted from. Apple mass a significant amount of valuable extractive substances. The steaming water must be used to dissolve the preservative added to the puree, or to fill in the burrs in the secondary flock, before wiping them; Otherwise significant losses of extractive substances of apple are obtained. When water leopard inevitably lost vitamin C, which easily passes from the apples into the water.
Known scalding water advantage is that it provides a more mild hydrolysis of pectic substances than steam, since in the first case apple temperature does not rise above the boiling point of water.
For steam scalding of apples used in large enterprises aids continuous different types: basic requirements provided for in respect of these devices are as follows: a) the maximum relief load and unload apples on scalding, b) prevent crushing and packing apples in shparitelya during scalding c) uniform proshparivanie all apples d) the minimum contact with corrosive metals apples,
d) reduction of losses through proper drainage shparochnoy water and condensate, and their use, e) the elimination of isolation in a couple of shparitelya premises.
Soviet engineers developed a number of designs continuously operating shpariteley screw and shaft type.
In the preparation station, fruit and berry puree Zhitomir confectionery factory installed two shparitelya screw type.
Screw the unit (Fig. 4) consists of a screw 1, the prisoner in one or two one above the other buildings trough 2, 3. Recent made of stainless steel (or tree) with a sealed lid. stainless steel screw has a hollow shaft 4, connected to the steam pipe. On the surface of the shaft are openings for steam sparging. Download apples in the auger is made through 5 bunker.
During scalding apples are moving through the upper screws and then the lower body; proshparennye apples are unloaded through 6 hatch.
When scalding sulfited apples in this shparitele necessary to provide extraction systems for removal of sulfur dioxide.
Shpariteli this type are characterized by their compactness and high performance to 12 tons of apples per shift.
Fig. 4. Screw shparitel.
Greater attention should be paid shpariteli mine type. They stiffened continuous movement performed by apples (or other large fruits) by gravity proshparivaemogo raw materials and a static pressure of the overlying layers of apples in the underlying.
These shpariteli differ cheapness (a simple wooden structure) and the lack of moving working parts inside the machine. They are well justified in practice.
The Lysyansky scraper (Figure 5) consists of a vertical receiving box 2, which ends with an inclined box - the 1 scraper. Angle of the bottom of the spar to the horizon 20 °. Steam bubbaters are laid at the bottom of the spar. Raw material is fed by means of a bucket elevator from the top to the receiving part of the apparatus, from where it enters the scoop. At the exit of the crane, the 3 thrust damper accelerates, slows or temporarily stops the escape of the raw material. This achieved regulation of the time and degree of scalding. The damper actuator is in gear with a handwheel. After leaving the stirrer, the evaporated apples are sent directly and the loading funnel of the wiping machine.
Fig. 5. Shparitel Lysyanskogo.
Shparitel Dmitrieva (Fig. 6) works on the same principle, but differs in some details of the device. It is a wooden riser divided by a partition into two longitudinal shafts. elevator Apples are continuously fed in the top opening system, and from the lower outlet of continuous output shparenye apples.
Each office unit on its vertical axis is the tube bubbler, not reaching approximately 0,5 m to the top edge of the device. The steam sparger in is supplied from below. The narrow cross-section of the shaft (0,5 X 0,5 m) and central (Axial) location bubblers create the conditions for even scalding apples. The holes on the tube sparger are arranged in decreasing amount in the direction upwards, which ensures maximum flow of steam at the bottom of the mine, and the minimum - at the top.
To avoid thinning mashed condensate and is obtained by scalding juice at the bottom of the cone-shaped part of the device, in the rear wall, located opposite the discharge opening, are made longitudinal slit width of about 10 mm, through which the mixture of condensate and the juice flows into a funnel and from there through the chute going one way or otherwise.
To ensure even settling of apples over the cross section of the mine and for directing condensate mixture with grating for the swelling of their juice from the discharge outlet is arranged ledge.
The discharge opening is formed in a slightly protruding tube, overlapped metal valve connected through a comb and gear with the steering wheel. The duration of scalding is regulated by means of this valve.
In the apparatus described, the formation of the fruit is effected by the direct action of steam. This ensures better use of steam heat. However, when the vapor condensates in the evaporated mass, the latter, respectively, dilutes. Therefore, in Dmitriev's sprays, etc., the formation of the resulting liquid from the sparred apples is envisaged in order to increase the content of dry substances in the puree. The mixture of condensate and apple juice that has been evaporated from the stirrer is collected separately from the puree and used in various ways. So, for example, it is subjected to thickening and added in puree. It is very useful to reduce the amount of condensate produced by preheating the apples to 50-60 ° before steaming with deaf steam in special auger heaters or in hot water baths.
for the steam scalding of apples on small businesses use shpariteli Cabinet, box, closed, and the usual type steamers Gents, is used to park the potatoes in an alcohol and starch and syrup industries. These shpariteli differ from each other in a process load of apples (immediate loading, loading trucks on a sieve), by the method of discharging shparenyh apples, steam heating process (coil or bubblers) and t. D.
scalding apples mode in specific conditions of production set depending on the type of shpariteli, vapor pressure, apples, their size and degree of ripeness.
In practical work, the following provisions must be followed in the process of pouring: all apples should be as far as possible and equally spaced, after scraping the apples should leave unbroken, as this prevents the loss of apple juice, especially when the spar is not in direct connection with the wiper machine . When the apples overheat, that is, when they are overgrown, some of the apples are cooked. If the apples are not matted, then areas that are not subjected to high temperature, containing untouched oxidases remain in the zone adjacent to the central part of the apple. Because of this, darkening of the apple mass, usually starting from the core layer, is possible.
Wiping shparenyh apples
Shparenye apples sent to the rubbing, the main purpose of which is to separate the inedible parts (stalks, seeds, seed boxes, etc.) From the pulp and refinement of the latter.
Apples rubbed on various designs machines. The most common Wiping machine of horizontal type (Fig. 7).
Fig. 7. Driving a cleaning device for machine shparenyh apples.
Prepared with a knife apples (or other fruits) are fed through the loading (6 funnel into the cylindrical body of the machine, mounted on the 3 shaft and consisting of a double-sieve 1.
An auger is mounted on the shaft on the inlet side of the machine, pushing the post - drank apples to the crushing blade 4, from there the pre-shredded apples go through the 5 spreading grid into the working space of the machine, in which two or four bends are rotated, mounted with special holders on the same shaft. Attached rubber pads along the outer edge of the 2 beat. The protruding outer edges of the latter form a small gap with the inner surface of the sieve cylinder, the value of which can be adjusted within 2 — 5 mm by displacing the blow holders.
The number of revolutions 500, per minute.
Under the influence of the centrifugal force developed by rotation of the beat shparenye fruit discarded to the periphery of the cylinder are pressed against the mesh and the pulp is forced out through holes in the car radio.
Remaining inside the cylinder of the apple (t. E. "Vyterki") detained sieve, are removed from the machine through the hatch.
The progress of the breezes to the exit is due to the fact that the fruits entering the body of the machine receive, in addition to the rotational movement, also a translational movement in the direction from the hopper to the ejection hole, which is achieved by mixing the beams with respect to the generatrix of the cylinder of the machine by some angle , So, the angle of shift or advance.As this angle increases, the translational velocity of the fruit mass increases, while decreasing the yield of the fruit pulp through the grid by increasing the number of bites. The angle is chosen in accordance with the type and variety of fruits in the range from 1,5 to 5 ° so that the wipers contain a minimum amount of fruit pulp.
The rate of advancement vyterok also depends on the size of the openings of the working screen machines, which regulate the passage of pureed flesh and crushing the latter.
To wipe shparenyh apples used mesh with a hole diameter 1,5-2 mm. In secondary rubbing mashed potatoes immediately prior to its use in the production of marmalade-Pastila products used nets with smaller holes (from the 0,5 3 to mm).
Wiping machine manufactured in different sizes with a capacity of up to 1 10 t / hour (for apples).
All working parts in contact with the mash, must be made of non-oxidizing metal. Often the copper mesh used to rubbing, are a source of contamination of fruit and berry puree copper. Application components of copper or iron adversely affect the durability of vitamin C of the feedstock. Most suitable for this purpose, the material is stainless steel.
When working on wiping machines need attention and uniform as possible a continuous flow of shparenyh apples, as otherwise possible overloading of the machine grid. Special attention is required Protection against foreign objects in the wiping out of the risk of spoilage and mashed grid gap.
It is very important for the control of the release of mashed potatoes, which depends on the quality vyterok (vyterki should be possible to fully exempt from the pulp). Do not allow crushing of seeds, as this may lead to the transition from seed and amygdalin mashed appearance in the last paragraph of bitter taste.
Primary vyterki contain about 24-32% dry matter, including 3-6% of sugar, 1,0-1,5% pectin for calcium pectates, 10-12,5% crude fiber.
The wipers are usually subjected to secondary rubbing to remove an additional amount of gelatinous puree from them. For this purpose, they should be collected immediately from under the wiping machine in collections equipped with coils for heating. The wipes are poured with two or three times the amount of water by the weight of the breezes, and the whole mass is secondarily evaporated within 30 min., Then again directed to the wiping machine. The resulting puree is used for the lower grades of marmalade, waste - secondary cuttings - for the production of pectin. If the pectin content is too low, or if it is impossible to process them in situ on pectin, they are immediately disposed of in the feed.
For transportation puree with rubbing on the next stage of production pumps mainly used revolving type.
Sometimes it is beneficial (depending on equipment location) using screw devices for moving the purée. The screws can also be used for transporting apples shparenyh on rubbing and rubbing with vyterok.
Apple puree, like other types of fruit and berry puree, is a substrate of predominantly carbohydrate character, favorable for the development of yeasts, molds and some acid-forming bacteria. Getting in mashed potatoes, yeast causes alcohol fermentation in it. Since the original microflora of apples perishes in the process of their lapping, the contamination of mashed potatoes by these microorganisms is possible only as a result of the so-called "secondary" infection in the further stages of production following the scalding. The natural protective factors from microbiological spoilage of mashed potatoes are its acidity, a relatively high concentration of hydrogen ions (pH) and a thick, viscous consistency. The higher the acidity and viscosity of the puree, the better it resists the development of yeast in it. However, in order to protect against mashed potatoes intended for long-term storage, it becomes necessary to artificially preserve it, for which the following methods can be used.
Sterilization of heat
Fruit puree sterilized jars (capacity of about 10-15 l) of tinplate or glass, similar to other fruit and berry preserves. With proper sterilization is achieved obesplozhivanie complete and best preserved apple sauce. The disadvantages of this method of preservation is its labor intensity and high cost, which makes it unprofitable for the mass of the workpiece.
Drying. Reducing the water content of the purée to 15-20% by drying also provides the necessary guarantee of the damage it during storage. (Drying method puree will be described separately).
Poddarka with sugar. When the apple sauce is cooked with sugar in a ratio providing a sugar concentration in the product of not less than 60-65%, the development of microorganisms is strongly delayed. Procurement of apple puree, as well as other types of fruit and berry puree in the form of podvarok, is practiced widely in the confectionery industry. However, with this method of harvesting, aromatic and gel-forming properties of the puree are lost to some extent. Therefore, apple puree, harvested by boiling with sugar, is of little use for the production of marmalade-pastille products, it is used in this form mainly for fillings.
The puree to be frozen immediately after the scalding is mixed with sugar in an amount of about 25% to the weight of the whole mixture. Filled in barrels (or in tin cans, as well as in cans of special compressed cardboard) purees are quickly frozen in unclosed barrels in freezers with air circulation. After freezing, the purees of barrels or cans are clogged. In this case, the freezing speed of the puree, which depends on the temperature, air movement, dimensions and material of the mashed potatoes, is important. Freezing of apple puree does not affect its gel-forming and taste properties, provided that the puree is not subjected to prolonged warm storage after thawing.